fails with an error message
"could not find a version that satisfies the requirement python-opencv ( from versions)
no matching distribution found for python-opencv"

Any ideas what the problem is ?

Also, I know I have read somewhere about piwheels and opencv but can't find the article, not sure if it was in pi-weekly or magpi.
If you know where the article was published I would be grateful for a link, just to put my mind at rest! I have gone though some of the back issues of pi weekly and tried googling but have not found a link.